Compensating valve



`SlPElTCElEt G. NEAL, OF lil'lEW YORK, N. Y., .ASSIGNGR T0 .iUTUlJIALlCSTRAIGHT 1133i BRAKE COMPANY, OF XWILIWNGTON,

WARE.

DELA'WARE, A CORPORATON OF DEltlf COMPENSATING VALVE.

Application lecl January 3, 1921. Serial No. 434,738.

To all whom t may concern Be it known that l, SPENCER G. NEAL, a citizen of the United `States, and residing in the borough oit Manhattan, city, county, and State of 2ew -lorlnhave invented certain new and usefullmprovements in Compensating Valves (Case No. 39), of which the following is a speciiication.

This invention relates to improvements in that type of compensating valves shown in Patent No. 1,089,579, dated March 10, 19141, and also shown in Patent No. 1,311l,975, dated September 2, 1919. These compensating valves are operated by equalizing reservoir pressure and brake pipe pressure and control a connection betweenthe main reservoir and the i. brake pipe and between the brake pipe and atmosphere, and maintain a yuniform brake pipe pressure.

lThe object of this invention is to provide `rneans to insure a rapid reduction in equalizingreservoir pressure when the engineers brake valve isplaced in emergency position for the purpose of securing an emergency application oi the brakes. llVhen `the engineers brakefvalve is placed in emergency position, there is a very rapid reduction in brake pipe pressure and a slower reduction in equalizing reservoir pressure, and it is the object of this invention to provide means lor quickly reducing the equalizing reservoir pressure to zero, or approximately so,in order to insure the rapid operation of the com `pensator in emergency applications ot the brakes and to prevent the main reservoir pressure exhausting through the compensa tor. Another object ofthe invention is to provide Ameans .whereby the equalizing reservoir venting means will not operate during all slowservice reductions in brake pipe pressure, but will only operate on a sudden reduction in brake pipe pressure designed to secure an emergeny application of the brakes.

ln the drawing:

Fig. 1 is a diagrammatic view showing the compensator and its connections to the engineers valve and the main reservoir and equalizing reservoir; p

Fig. 2 is a vertical sectional view of the compensating valve; and

Fig. 3 a similar view taken on the line Ille-HI ot Fig. 2.

Referring to` the various parts by numerals, 1 designates the compensating valve; 2 the engineers brake valve; 3 the main reservoir; and 4 the equalizing reservoir. The brake pipe 5 is connected to the enginees brake valve by pipe 6, in the usual manner, and is connected to the compensator by pipe 7 ,the latter pipe being connected to the compensator at 8. rllhe main reservoir is connected to the engineers valve by pipe 9` and to the compensator by pipe 10, said pipe being connected to the bottom ci' the compensator at 11. The equaliaing reservoir is connected to the engineers valve by pipe 12 and to the compensator by pipe 13, said pipe being connected to the compensator at 1a. All of these pipes are provided with the usual cut-oil valves 15. The engineers valve may be modiiied, as described in Patent No. 1,089,579 and also in liatent No. 1,314,975, to render the equalizing discharge piston inoperative, so that the brake pipe exhaust will be secured through the compensating valve.

rlhe main operating parts of thecompensating valve are constructed substantially as shown in Patent No. 1,314,975, and comp i a casing in which is arranged a diaphr 16 from which depends the valve-operl yoke 17. rllhe diaphragm 16 divides tl:

chamber 18 which is in communication with the equalizing reservoir lthrough pipe 13; and a lower brake pipe chamber 19 which is at all times in communication with the brake pipe 5 through the branch pipe 7. A release valve 20 is connected to the yoke 17 and is provided with a depending winged portion which travels in a valve cage formed at the inner end ci? an exhaust passage 21.` The yoke 17 at its lower end is provided with a horizontally extending arm 22 which is in alignment with the stem of an upwardly seating supply valve 23. The 22 is formed with a depending annular guide flange which engages a rigid lguide carried by the valve casing. It is obvious that when. diaphragm 16 is depressed by a superior pressure in the equalizing reservoir chamber 18. the exhaust valve ,2O will be closed and the supply valve 23 will be opened. It isalso obvious that when the brake pipe pressure in chamber 19 is superiorl to the pressure in chamber 18, the exhaust valve 20 will be opened and the supply valve 23 will be closed,because et the lostmotion connection between the yoke 17 and valves 24 and 27 There is a point in the movement oic the diaphragm 16 at which both or' said valves may be closed. This also insures the closing` of one valve betore the other valve is opened by the movemento1t the diaphragm.

The release valve 2O is formed with an upwardly extending neck 24 terminating in a head 25. The yoke 17 is provided with a forked portion 26 which receives the neck 24 and connects the release valve to the yoke. y

The supply valve 23 is guided by winged portion 27 and is held yieldingly to its seat by a spring 23 which. normally forces the v ve upwardly. rEhe space in the casing -helo'w the supply valve 23 is in communieation with the main reservoir through pipe 10. so that whenever said valve opened through the operation of the diaphragm 16, main reservoir air will `How into the chamber 19 and thence to thebrake pipe through opening 29. A

1When the engineers brake valve is placed in emergency position, brake pipe pressure is exhausted throughthe brake valve more rapidly than the equalizinp', reservoir pressure is reduced. The result of this is that the pressure in the ecpializing reservoir chamber 18 ot the compensating valve will, during a certain period, exceed the pressure in the brake pipe chamber 19 of the compensating valve and the diaphragm 16 will be depressed during that period of timel and the supply valve 23 will be held open. During this period the main reservoir air will pass through the compensating valve to the brake pipe and then to atmosphere through the engineers brake valve. until the pressure in the qualizing reservoir has been exhausted, at which time the supply valve 23 will be closed.

To immediately exhaust the equalizing reservoir pressure upona sudden reductionl of brake pipe pressure, l provide the equalizing reservoir vent valve 30. This vent valve consists of a casing 31 secured to the compensating valve casing; andprovided with an interior bushing' 32, The bore of this bushing is enlarged at its inner end to form the piston chamber 33. In this piston chamber is mounted a piston 34 having an outwardly extending stem 35 which carries at its outer end a guide head 36 which is designed to reciprocate in the bore of the bushing 32 near the outer end thereof. Connected to the piston stem is a small slide valve 37, the interiorof the bushing 32 forming the seat for saidy valve.

The seat of the slide valve 37 is formed with a port 38 which is connected by an annular passage 39 with -a passage 40 which leads to the equalizing` reservoir chamber 13. The said valve seat is also formed with an exhaust port 41 leading direct to atmosphere; and the slide valve if# iformed with a release groove. 42 which when tbc valve is in release position comici-ts the. port 2lb; to the port 41. as shown in Figi'. 2. and permits the equalizing reservoir chamber is lo exhaust to atmosphere.

The bushingT 32 forms a chamber i3 which It is obvious that a risingbrake 'pipe pressure will force the piston 311- toward the left hand, or inwardly, and .more the slide valve 37 to close the port 38. The piston provided with an annular rib 50 which is adapted to engage a `gasket when at the inner limit of' ,its movement to thereby seal chamber 43 from the tank except Vl'or the small leak port 49.

During; all slow reductions in brake pipe pressure, air will tlow from the tank Lli'i through leak port i9 into chamber Al-) and thence into the bake pipe chamber lll. anfl there will be no movement ol? the piston 31V and slide valve 37. lVhen. however. there i` a sudden reduction ot brake pipe pressure for the purpose of securing an emergency application oilz the brakes. the reduction o l' pressure in chamber 19 and also in chamber 43 will be too rapid to permit a n equal" ization of pressures on opposite sides olt the piston 34. The trapped pressure in tank 45, consequently` will move the piston ill outwardly and the slide yalve 37 will place port 38 in communication with exhaust port 41, so that equalizine' reservoir pressure in chamber 1S will be. exhausted to annosphere. This will prevent a downward movement oi" the diaphragm 16 and the opening oli the supply valve 23. The vent 'alve parts will remain in this position until there is an increase in brake pipe pressure whereupon the piston will be moved inwardly and the pori 38 again closed by the slide valve 37.v

lll/vliet l claim is:

1. The Combination. ot a compensatinpr valve adapted to be operated by opposed brake pipe and equaliziirgj reservoir pressures, and a vent valve adapted to be open ated upon a sudden reduction in brake pipe pressure to vent the equalizing' reservoir to atmosphere.

2. The combination ol' a compensating` valve adapted to be operated by opposed brake pipe and equalizine reservoir pressures, a vent valve adapted to be operated upon a sudden reduction in brake pipe pressure to vent the equalizing,- reservoir to atlull " `;reservoir chamber, the supply valve being `Opened when the equalizing reservoir cham-- inosphere, and means to permit said rent valve to remain inactive during all slow reductions or brake pipe pressure.

3. A compensaring` valve eoinprisingv 'a easing, a diaphragm therein and forming an equalizing reservoir ehainberuand a brake pipe chamber1 supply valve, a release valve,.'both of said valves being adapted to be` operated by said diaphragm in response to Variations ol pressure in the equalizing Y ber pressure exceeds the pressure in "the `brake pipe chamber and the releaseval've being .opened when the equalising` reservoir pressure is below the brake pipe pressure, a Vent valve for the equalizing' reservoir chamber, and means whereby said valve will remain inaetive'during` all slou7 Changeset pressure in the brake pipechainber but will respond toa sudden reduction or pressure in the brake pipe chamber to `open said vent Valve and exhaust the air freni the equaliz ing chamber to atmosphere. fl. A compensating valve comprising a,

` easing, a diaphragm therein and forming an equalizing reservoir chamber and a brake pipe chamber7 a supply Valve, a. release `side to the pressurev in the brake pipe charnber and on the other side to a trapped pres reservoir chamber, th

sure. means 'for slowly equalizing the pres- "su res on opposite sides of said piston Where-f by a sudden reduction oi! pressure in the brake pipe chamber will permit the trapped pressure to move said piston, and an exhaust 'valve adapted to be moved by said piston to open an exhaust port from the equalizinfr reservoir chamber upon a sudden reduction oit pressure in 'the brake pipecharnber.

5. A compensating valve comprising a easing, a diaphragm therein and 'forming au equalizing reservoir ch amber and a brake pipe chamber. supply valve, a release valve, both et said valves being; adapted to be operated by said diaphragm in response to Variations of pressure in the equalizing supply Valve being opened when the equalizing reservoir chainber' pressure exceeds the pressure in the brake pipe chamber and the release valve being opened when the `eqnalizinp,` reservoir pressure is below the brake pipepressuren a vent Valve 'for "the equalizing reservoir chamber Comprising a casing7 a piston therein dividing said casing,- into two chain` bers. a leali Jort formed throueh the eisten and connectine' said two chambers, a passage connecting the chamber at one side oit said piston to the brake pipe chamber7 a tank connected, to the chamber on the otherk side or said piston," an exhaust valve adapted to be inored by said piston, whereby upon slow reductions oit the pressure in the bralre pipe chamber the piston will remain inactive and the exhaust Valve closed7 the piston being moved `by the trapped pressure when the reduction cie pressure in the brake pipe chamber is sudden.

ln testimony whereof l hereunto allie: 'my

signature.

SPENCER G. NEAL. 

